1. Field of the Invention
This invention relates in general to apparatus and method for a multiple branching light wave guide functioning according to the beam splitter principle wherein a number of aligned guiding channels are mounted parallel to each other in one plane in a body, which are divided by a mirror layer mounted at an inclined angle relative to this plurality of channels for coupling energy between the horizontal channels and other light wave channels which extend at right angles to the first light wave channels.
2. Description of the Prior Art
Light wave guide branching elements which operate according to the beam splitter principle are known in which a plurality of aligned guidance channels are mounted parallel to each other in one plane in a body and are separated by means of a single mirror layer which is mounted at an angle relative thereto and in which additional guidance channels extend from the mirror layer and substantially at right angles to the first guidance channels so as to form a simple branching element.
Such individual branching element is easy to manufacture since parts of the branching element can be processed in blocks during the various method steps such as, for example, by aligning the light wave guides with respect to each other and the cost for the individual branching elements can be reduced inversely proportional to the number of individual branching elements manufactured. The simultaneous manufacture of many identical individual branching elements can be accomplished by cutting blocks parallel to the planes of the light wave guides. The individual branching elements can be then interconnected to form multiplexers and demultiplexers as is required in communication or data transmission wherein the various channels are separated in wave length so that multiplex operation can occur with single fiber systems on the input side of the channel junction and on the output side for the channel separation. The mirror layers must be designed as edge variable filters having different spectral responses relative to the edge of the filter. For this purpose, first a number of blocks with different matching element multiples must be manufactured. Such multiplexer/demultiplexer is described for four channels in the publication entitled Siemens Forschungs und Entwicklungsberichte, Vol. 8, No. 3, Pages 130-135 (1979).
Such multiplexer/demultiplexers require (p-1) different edge filters for p-channels with the edge filters having to be individually vapor deposited per block as a respective dielectric multiple layer structure.